The first of a series of ordinations are set to take place, which will see former Anglican clergy defect from the Church of England and become Roman Catholic priests, on Saturday.

Overall more than 50 former Anglican clergy will complete their defection over the next two weeks in a series of Pentecost ordinations.

The first of these will see seven former Church of England clergy be ordained in London by the Most Rev. Peter Smith, Archbishop of Southwark. The event will further establish the new Ordinariate formed by Pope Benedict XVI for Anglicans that wished to defect from the Anglican Church of England in protest against its moves to accept women bishops.

In excess of 900 laity have already moved to the Catholic Church and have been waiting for their clergy to complete training for Catholic priesthood at a seminary in West London.

As the former Anglican clergy become ordained as Catholic priests, they will lead groups of former Anglican laity to branch off from the core Catholic congregations to worship as a separate Ordinariate group. The Vatican will soon publish a separate liturgy for these Ordinariate groups to follow.

According to The Times in London, Keith Newton, who heads up the Ordinariate, has explained that dozens more Church of England clergy are currently also considering their positions within the Anglican Church.

Newton told The Times, “Every week somebody writes or e-mails asking how they can join the Ordinariate. They are often people I have never heard of before.”

Explaining the risk facing those defecting to the Catholic Church, Newton commented: “For clergy it is a practical risk, meaning they abandon tied housing and a guaranteed stipend for a smaller income and uncertainty.”

Newton, himself defected and became a Roman Catholic priest in January this year. He and Andrew Burnham and John Broadhurst – all former Anglican bishops – were welcomed into the Roman Catholic Church during a ceremony at Westminster Cathedral in London.

The three made the move because they were "distressed" by the developments in the global Anglican Communion which they found to be "incompatible" with Christian tradition.

The Vatican announced in 2009 that it would introduce a new church structure that would allow former Anglicans to enter into "full communion" with the Catholic Church while preserving their Anglican traditions.

Pope Benedict XVI made the provision in response to the numerous requests he received from Anglicans who were unhappy with the ordination of women and noncelibate gay bishops.